Sensitive fuses



June 1'7, 1958 G. CORSI 2,838,999

SENSITIVE FUSES Filed March 2. 1955 INVENTOR GIANNINO CORSI ATTORNEYS I 2,838,999 Patented June 17, 1958 lice SENSITIVE FUSES Giannino Corsi, Rome, Italy, assignor to Bombrini Pardi-Delfino, Rome, Italy, an Italian company Application March 2, 1955, Serial No. 491,585 Claims priority, application Italy April 27, 1954 3 Claims. (Cl. 102-72) This invention relates to a sensitive or extra-sensitive percussion fuse provided with self-destruction means operating after a predetermined period.

According to the present invention there. is provided a fuze having a body axiallybored with a hollow striking pellet coaxially arranged in the axial bore of the body and containing an ignition train formed of a front priming cap, a delay element, a match and a rear priming cap, all the elements forming the train being arranged in alignment and in immediate succession to each other, the rear priming cap being arranged to be ignited either upon impact thereof against an ignition needle upon striking of the fuze against a target or through direct ignition from the said match if the target is missed.

The striking pellet is fastened to the fuze body by means of a metal latching element which is arranged transversely of the body of the fuze and to be disengaged from the striking pellet to permit the axial displacement of the latter only after the delay element burns.

The main advantages afforded by this invention are:

(a) An operative and constructive simplicity of the fuze which can be embodied with the maximum economy of materials, as well as of machinery and of labor;

(b) Absolute perservation of the gunpowder against the action of atmospheric agents without need of a sealing cap;

(0) Stability of the safety device the latching and supporting action being obtained by a metallic element which is easily slidable owing to its eccentricity;

(d) Easy overhaul of the fuze by simple substitution of the striking unit;

(e) Possibility of forming the main body of the fuze using low cost materials such as iron or a moulded synthetic resin. I

The invention will be described attached drawing, wherein:

Figure 1 shows an axial section of the fuze;

Figure 2 shows a right side elevation of the device of Figure 3;

Figure 3 is a cross-sectional view of an alternative system for trajectory safety device, according to this invention; and

Figure 4 is a left side elevation of ure 3.

In Figure 1 of the drawing the reference numeral 1 indicates the body of the fuze provided with an axial bore wherein the striking pellet 4 which is axially bored is located. In the front portion of the striking pellet 4 an ignition cap 2 is arranged which is held in fixed position by a spring 3 and protected by a metal disc 16 inserted in the striking pellet. Facing the ignition cap 2 there is an apertured needle housed in a recess made inside the pellet 4.

In the axial bore of the striking pellet 4 there is a match 13 formed of compressed gunpowder which comprises a part 14 which acts as a delay element for the trajectory safety device. Between the match 13 and with reference to the the device of Figplaced, overcoming as soon as two conditions have been attained, iv e.:

the delay element 14 a transverse hole 17 is provided and in the wall of the striking pellet 4 there is provided a hole 6 for the passage of the flash efiect from inside to outside of the striking pellet.

In the rear portion of the striking pellet there is arranged a priming cap 9, which faces the apertured needle 12 carried by the plug 18 of the body of the fuze. Between the priming cap 9 and the needle 12 there is interposed a pawl 10 which freely rotates about a pivot 11. In the front part of the body of the fuze a recess 19 is provided registering with the hole 6 in which recess a latching element 8 is located which in the position shown in Figure 1 acts as a safety stop member for the striking pellet 4. The latching element 8 is axially bored and is provided with a cavity wherein a gunpowder charge 15 is contained. The recess 19 is closed by a sealing plate 7.

In the embodiment shown in Figure 3 the safety element 21 is provided with a second cavity containing an auxiliary delay charge 22.

The operation of the fuze is as follows:

When the projectile is fired the ignition cap 2 is disthe resistance of the spring 3, it strikes the apertured needle 5 and by its combustion ignites the compressed gunpowder match 13, the first portion 14 of which forms the delay ofthe trajectory safety device. When said delay 14 has been burned, the ignition is transmitted through the hole 6 and the corresponding hole of the metallic latching element 8 to the gunpowder charge 15 therein contained which, on bursting, ejects the sealing plate 7 thus allowing the safety element 8 to be ejected due to centrifugal force 9 i The fuze is cocked and is ready to act against a target ,the pawl 10, pivotedon the pivot 11 and held by a blocking element (not shown) has been displaced by centrifugal force, which can occur only when the acceleration of the projectile has ceased asuntil then the force exerted by the striking pellet 4 bearing into a recess in the pawl, keeps it in its safety position; (2) the delay element 14 has been burned and the metallic latching element 8 has been ejected; only when these conditions have been attained the striking pellet 4, when the fuze strikes a target, is able to move back and the priming cap 9, carried therein, striking the apertured needle 12, detonates thus causing 'detonating the detonator placed below it. On the contrary if the projectile does not strike the target and continues its free path, the match, 13, Continuing its combustion, causes, after a pre-established numberof seconds, explosion of the priming cap 9 and therefore the self-destruction of the projectile.

Without altering the system in which the delay match is inserted within the striker, several variations can be easily provided for.

I claim:

1. A percussion fuse for projectiles having a mechanism for self-destruction after a predetermined time comprising a fuze body provided with an axial bore and a rear recess in a continuation of said bore, a plug screwed in said recess and provided with a rear holed needle axially positioned in said plug, a hollow striking pellet coaxially arranged in said axial bore of said fusebody, said striking pellet containing an ignition train comprising a fore priming cap, a delay charge, a match and a rear-priming cap, said elements comprising said ignition train being in alignment and directly succeeding one another, said ignition train further containing a holed needle interposed between said fore priming cap and said delay charge, said rear priming cap being in ignition relation with said holed needle of said plug, said hollow striking pellet having a wall provided with a transverse bore opening at the bottom of said delay charge, said fuse body being provided With a transverse bore registering with the transverse bore of said striking pellet, a metallic latchirig element slidably arranged in said transverse bore of the fuse body and engaging saidstriking pellet preventing it from moving rearward with respect to the fuze body, retaining means fastened to the said fuze body at said transverse bore of the fuze body to keepsa id latching element inside said transverse bore and to hinder the sliding of said latching element and removal thereof from the fuze body under the action of centrifugal force until the delay charge of said ignition train has been ignited, burnable means contained in said latching element and arranged to be ignited by the flash of said delay charge, whereby the ignition of the burnable means causes the removal of said reatining means and the expulsion of the latching element from the fuze body under the action of centrifugal force.

2. A percussion fuze for projectiles having a mechanism for self-destruction after a predetermined time, which comprises a fuze body provided with an axial bore and a hollow striking pellet coaxially arranged in said axial bore, said striking pellet having a length substantially equal to the length of said axial bore of the fuse body, said fuse body being provided with a rear recess in a continuation of said axial bore, a plug screwed in said recess provided with a rear holed needle axially positioned therein, an ignition train contained in said striking pellet comprising a fore priming cap, a delay charge, a match and a rear priming cap, arranged in alignment directly succeeding one another, said ignition train further comprising a holed needle interposed be tween said fore priming cap and said delay charge, said rear priming cap being in ignition relation with said holed needle of said plug, a pawl pivoted at one end interposed between said rear priming cap and said rear holed needle of said plug when the fuse is inoperative and being arranged to rotate about the pivot under the action of centrifugal force only after a predetermined interval after the firing of the projectile, said hollow striking pellet having a wall provided with a transverse bore opening at the bottom of said delay charge, said fuse body being provided with a transverse bore registering with the transverse bore of said striking pellet, a metallic latching elernent arranged in said transverse bore of the fuse body and engaging said striking pellet preventing it from moving rearward with respect to the fuse body, a sealing plate closing the outer end of said'transverse bore of the fuse body to keep said latching element in said transverse bore and to hinder the sliding of said latching element and the removal thereof from the fuse body under the action of centrifugal force until the delay charge of said ignition train has been ignited, said latching element being axially bored and provided with a recess facing said sealing plate, a powder charge contained in said recess and arranged to be ignited from the flash of said delay charge, whereby the ignition of the powder charge last mentioned causes the removal of said sealing plate thus permitting under the action of centrifugal force the sliding and the expulsion of said, latching element which makes free the rearward movement of said striking pellet with respect to the fuse body.

3. A fuse according to claim 2, wherein said latching element is provided with two end recesses connected with each other by an axial bore, each of said recesses containing a powder charge arranged to be ignited by the flash of said delay charge with the burning time of said powder charges acting as a further delay to the expulsion of said latching element.

References Cited in the file of this patent UNITED STATES PATENTS 1,216,834 Moren Feb. 20, 1917 1,237,816 Rimailho Aug. 21, 1917 1,491,676 Courouble Apr. 22, 1924 1,944,623 Varaud Jan. 23, 1934 2,014,393 Mathsen Sept. 17, 1935 FOREIGN PATENTS 26,909 Great Britain 1907 10,219 Great Britain 1913 14,890 Great Britain June 27, 1913 

